Lone Sentry: Westwall, Springboard of 1940, Assumes Defensive Role (WWII Tactical and Technical Trends, No. 51, October 1944)

The German Siegfried Line—called by the Germans Der Westwall—was being probed by Allied patrols as this was being written. By the time this publication reaches the reader the Westwall may have been flanked, breached, or jumped by an airborne Allied Army, relegated to the limbo of outmoded military works, and forgotten except in military textbooks.

On the other hand, the Westwall may prove to be a formidable barrier. In 1939 the Germans boasted the Westwall zone—8 to 20 miles deep—was "ready to crush every attack in the bud and tear to pieces with its gigantic shells every hostile lineup of troops, not only close to the Rhine but also far behind the enemy's deployment zone"—where Allied forces are at this writing.

But whatever happens to this modern version of an ancient Chinese idea,[1] it will be useful to know how the Westwall was built, and why, and to note the lessons to be drawn from its success or its failure.

The frontispiece illustrates a Westwall dragon's-tooth tank obstacle. The drawn insets show (1) 1 of 36 surface exits of a typical closed troop shelter, (2) an armored embrasure with stepped apron, (3) stepped embrasure opening with steel shield down, (4) illustrating how most Westwall weapons are moved to open emplacements for combat, (5) machine-gun crew leaving a bunker to fight from field fortifications, (6) antiaircraft gun-tower in an air-defense zone, (7) soldier coming out of a firing-chamber entry.

[Westwall tank obstacle and fortification details (WWII German Siegfried Line)]

Westwall tank obstacle and fortification details.

Ostensibly a defensive barrier which would immobilize the Western Powers while the Germans moved East, the massive Westwall system was primarily designed, according to German doctrine, for offensive purposes—a springboard from which the German armies could plunge with relative impunity into the heart of France. Burt this was a purpose held in abeyance while Germany moved in other directions—into Austria, Czechoslovakia, and Poland.

NEITHER A LINE NOR A WALL

The strategic principle of the Westwall is entirely different from that of the French Maginot Line. The latter was to be "invincible," a continuous wall of mammoth, connected underground fortifications, extending from the Swiss frontier to the Belgian border—where it stopped. But the Westwall—neither a line nor a wall—is a fortified zone some 400 miles long and 8 to 20 miles in depth. Within that area, Germany ingenuity worked with natural terrain to create a defensive as impregnable as humanly possible. Thousands of forts and pillboxes of reinforced steel and concrete—smaller than the forts of the Maginot Line—stud the region, carefully camouflaged as farmhouses, barns, country residences, and built deep underground.

Some of the works have been equipped with long-range guns, howitzers, mortars, antitank guns, flame throwers, and batteries of field artillery. Each fort and pillbox is located, not in a belt as in the Maginot Line, but integrated into the terrain to command a wide field of fire and cover the approaches to other fortifications. Difficult terrain along the French-German border—as well as the Rhine River—provides excellent cover for permanent as well as field fortifications.

The front zone, in general, consists of mine fields, barbed-wire entanglements, elaborate tank traps and barriers, and machine-gun nests. Behind this zone, which the French and British Armies did not attempt to penetrate in 1939-40, are the stronger reinforced fortifications in depth. And behind this second zone—in the original plan—was the "air wall," where Goering's Luftwaffe was to be concentrated.

The original Westwall extended only from Basel to Kleve, opposite Rotterdam. Since the war, the Germans are supposed to have extended the wall northward to Emden on the North Sea—how well may be revealed before this is read.

In technical detail, a sector of the Westwall is normally four independent zones deep:

1. Forward zone (Vorfeldzone)—contains field fortifications including trenches, barbed-wire entanglements, machine-gun emplacements, observation posts.

2. Main defense zone (Grosskampfzone)—comprises fortified structures such as shelters, pillboxes, casemates, and forts, and antitank obstacles covered by antitank guns. In addition, this zone has intermediate areas, front and rear, in which isolated works are placed at critical points along natural avenues of enemy approach.

3. Rear defense zone (Rückwärtige Zone)—much the same as No. 2, but not as strong.

4. Air defense zone (Luftverteidigungszone)—since antiaircraft defense in all areas was to be the responsibility of the Luftwaffe, this zone included both main and rear zones, as well as a strip extending 10 to 30 miles behind the rear zone. While AA defenses are scattered throughout this rearmost zone, most matériel is in the area immediately behind the rear zone.

TWO TYPES OF WORKS

Fortified works of the Westwall can be grouped into two classifications, shelters and emplacements, the latter comprising open emplacements, pillboxes, turrets, casemates, and forts. Shelters are strong, underground concrete works, with no emplacements for guns, designed to shelter large bodies of infantry and reserves from air and artillery bombardment. The German doctrine is to commit troops fresh as a unit, without casualties and without having had to endure the strain of hostile air bombing and artillery fire while waiting to attack. Some personnel shelters in the rear of the line of forts have turrets for observation and close defense.

Emplacements are either open or closed. Open emplacements, which reinforce permanent, closed fortifications, are designed for mobile artillery. Closed fortifications have four main designs: pillboxes, turrets, casemates, and forts. Pillboxes are small fortified positions designed primarily for light automatic weapons, mostly machine guns, although some light AT positions may be found. The embrasures are usually stepped to prevent the ricochets of enemy projectiles entering the port.

The majority of steel turrets are six-port types, with armor 7 to 10 inches thick. The turrets do not revolve; the Germans, unlike the French, do not consider revolving or disappearing turrets practical because they are complicated mechanisms easily jammed by hostile gunfire. One type of turret known to exist in the Westwall has steel inserts fitted into the ports to provide additional protection for instruments and small arms. Turrets may occasionally be mounted individually, particularly along ridge lines, but they are more often mounted in the roofs of concrete pillboxes to provide all-around observation and small-arms fire. The armament of a six-port turret is normally 2 AT guns and 4 MG's, with a crew of 6 to 10 men.

Casemates are strong, fortified closed emplacements primarily for artillery, with much thicker concrete protection than pillboxes. A group of interconnected casemates, pillboxes, and accompanying shelters, often with open emplacements nearby, constitutes a fort. There is usually provision for kitchens, ammunition storage, power facilities, etc., so the fort can operate independently of others if cut off. Underground passages to adjacent forts may be provided to facilitate relief of personnel, ammunition supply, and the care and removal of the wounded.

All pillboxes, casemates, and forts in the Westwall are so spaced as to provide interlocking fields of fire between adjacent works, yet they are not so close together that hostile artillery fire which misses one structure will hit another. Moreover, in accordance with German doctrine, concrete and steel works are supplemented by extensive field fortifications, to lend flexibility and mobility to the defense, to engage the enemy before he gets close enough to carry out close reconnaissance, direct fire, or demolitions, and to facilitate counterattack.

The majority of the works are linked with each other by communication trenches. For signal communication, there is a fairly extensive network of double cables between the works buried 6 1/2 feet in the earth. This telephone system is supplemented by other means of communication, such as radio and messengers.

Forts of the Westwall are to a great extent gasproof. The critical defending weapons can still fire through concentrations of gas, because they have gun shields which are made with fairly close tolerances. Rubber gaskets at the points of contact of metal on metal improve the sealing.

INDIVIDUAL FORTIFIED LINES

For readers who want to follow the fortunes of the Westwall on a map, here is a brief description of the wall and its features, from Basel on the Switzerland border northward to the Kleve-Munich (München) region. Several individual fortified lines are to be distinguished in the Westwall system:

1. Rhine Line—from Basel to Karlsruhe. Reserve position (Black Forest Line)—runs along the crest of the Black Forest (Schwartzwald), roughly from Säckingen to Baden-Baden.

2. Saar-Pfalz Line—runs from Bienwald through Bergzabern, a point south of Pirmasens, point south of Zweibrücken, St. Ingbert, Dudweiler, Merzig, Saarburg, to a point on the Mosel River southwest of Trier. Advance position (Saarbrücken Line)—extends from St. Ingbert through Saarbrücken to Merzig. Reserve position (Hunsrück Line)—runs from a point on the Rhine River south of Germersheim through Landau, a point south of Landstuhl, St. Wendel, to a point east of Trier.

3. Eifel Line—from junction of the Mosel River and Luxemburg border at Wasserbillig, along the frontier to the Belgian border, then along the crest of the Schneifel Hills to Schleiden.

4. Aachen Positions. Main line—from Schleiden through Steckenborn and Stolberg to Herzogenrath. Advanced line—from Monschau through Rötgen, a point east of Aachen (Aix-la-Chapelle), to Herzogenrath north of Aachen where it joins the main line.

5. Holland Position—from Herzogenrath through Geilenkirchen, a point east of Erkelenz, to a point 12 miles east of Munich-Gladbach.

At the southern end of the Westwall, the River Rhine marks the Franco-German border. Swift and wide. it has been considered a major obstacle. Here, the German defenses consist mostly of a double line of forts on the east bank at approximately 400-yard intervals. The first line enfilades the river. The second places its forts between gaps in the first line. Intervals between forts are shorter at bridges and likely crossings. Back of this double line are occasional short reserve positions blocking entrances to valleys leading into the Black Forest.

Three of the wall's strongest sections are in the strip from Karlsruhe to the Mosel, covering the Pfalzer Bergland on each side of the Saarbrücken Forest and the Weissenburg Gap. Strongest of these 3 sectors is that covering Saarbrücken: Here the line is double—the forward line continuous but in no great depth: the rear line a dense zone of forts approximately 2 1/2 miles deep.

The southern reach of the section from the Mosel River north to Kleve runs through mountainous and wooded terrain. Forts are placed in little depth. At Aachen (Aix-la-Chapelle) a double line rings the town. North of Aachen the line is reportedly weakest; in the Goch area, for instance, just south of Kleve, there are only four forts in 8 miles.

Prior to occupation of the Rhine in 1936, the Germans began work on defenses in the German interior on it secondary line running along the east bank of the Neckar River, from Heilbronn north to the River Main.

After the full of France, some of the Westwall wire entanglements were dismantled and some field works plowed in. Recently, however, they have been reported restored.

[1] The Great Wall of China, built in the Third Century B. C. by Emperior Ch'in Shih Huang Ti to keep out the Mongols, was 1,600 miles longer than the Westwall. Faced with granite blocks and bricks, it was 20 to 50 feet high, 15 to 25 feet thick. Much of it still stands.